Medieval bridge over the Esla at Mansilla Monument · Mansilla de las Mulas, Esla-Campos, León Image of Mansilla de las Mulas, not of the place itself. A work of eight barrel vaults and one hundred and forty-one metres in length, raised in the 12th century and rebuilt in 1573. Its fabric adds up to eight centuries of repairs and it is the obligatory crossing for pilgrims leaving the town for León. Photo: User:DoctorMaligno (Public domain) What to see and do in Mansilla de las Mulas